Dallas-based Comerica Bank’s Texas economic activity index improved by 0.2 points in December to a level of 91.8 points, from November’s index reading of 91.6, thanks to more oil drilling activity.

The index averaged 91.4 points for all of 2016, or 6.1 points below the average for the full year of 2015.

“The Comerica Bank Texas Economic Activity Index increased for the fourth consecutive month in December. This is the longest expansion streak for the Texas Index since mid-2014. Improving oil prices, more active oil fields and a stronger U.S. economy are the keys to better performance for the Texas economy this year. With oil prices firm through February we expect the Texas Index to continue to climb through early 2017,” Robert Dye, Comerica Bank chief economist, said in the report.